1. Field of the Invention
This invention relates generally to tape recorders and, more particularly, is directed to an improved apparatus to change the operating modes of a tape recorder by means of a feather touch push button operating through a trigger motor and which is suitable for use in battery operated portable tape recorders.
2. Description of the Prior Art
In prior art mode changing mechanisms for tape recorders solenoids are employed for each selected mode of operation, for example to move a head carriage assembly or for pinch roller displacement. These solenoids when activated require a constant current supply during the record or reproducing mode of the recorder. Since the solenoids used in these recorders are relatively large in order to maintain the head and pinch roller in operative position the current drain is inordinately large.
To obviate the disadvantage of the current drain incident with the use of solenoids, there has been proposed a mode changing apparatus wherein the solenoid is used only to effect a light triggering operation, i.e., the solenoid acts only as a trigger to convey the rotational output of a motor to an operating mode changing apparatus. Such a mechanism is disclosed in U.S. Pat. No. 4,167,764. The mechanism in the aforesaid patent has successfully reduced current loads and has permitted use of smaller solenoids than were employed in mode changing mechanisms theretofore so that power consumption was reduced.
However, in general where a portable tape recorder operating on dry cell batteries as a power supply is used, the reduction in the power consumption using the mechanism of the aforesaid patent is still not enough in order to obtain prolonged battery life.